Milling machine organization



Sept. 1, 1936. F, A. PARSONS l MILLING MACHINE ORGANIZATION original Filed Deo. 5, 1931 4 Sheets-Sheet 1 fr h nu Huhu ATTORNEY F. A. PARSONS MILLING MACHINE ORGANIZATION sept. 1, 193e.

4 Sheets-Sheet 2 Original Filed Deo.

F1 gl? A INVENW BY Y ATTORNEY MILLING MACHINE ORGANI ZATIO N Original Filed Dec. 3, 1951 4 Sheets-Sheet 5 Fl' .6. 81 52.4. A g

6 56 57 as J :fr -E kk- \;l\

l W ////i/ l 1 i Q l |`1 I 15524- 1 zzz 221 220 2m Fg 2 12a 217 O O f 217 54 Q 225% n y. i 94\ 64 es 125 /rf l fl/'75" "224 122 e, m m 34 226 :2. l 2325, s" 23a 5:

Sept. l, 1936. F. A. PARSONS MILLING MACHINE ORGANIZATION 4 Sheets-Sheet 4 Original Filed Dec. 3, 1951 N u@ m n., m m ss H l 0 H Y Patented Sept. l, 1936 MILLING MACHINE ORGANIZATION Wis.

Application December 3, 1931, Serial No. 578,684 Renewed January 30, 1935 s claims. (c1. :ao-21.5)

This invention relates to transmission and control mechanism for machine tools and more particularly for milling machines.

It isan object of the invention to provide mechanism in a milling machine for separating the Work and cutter during a portion of the operating cycle, particularly during backward movements, or during quick traverse movement of the table.

Another object is to provide a specific form of such a cutter and Work separating mechanism in which it is the cutter"` which is bodily moved during movement of separation.

A further purpose relates to provision of such mechanism which is, in part at least, of hydraulically operated type.

Another purpose relates to the automatic control of the machine including the above mentioned mechanism whereby the work and cutter separation will take place, when desired, without special attention on the part of the operator.

Another object relates to an improved combination of mechanism for purposes above mentioned with other structure and transmission and control mechanism of a milling machine.

Ano-ther object relates to an improved spindle supporting structure for a milling machine and improved mechanism for bodily spindle movement and particularly for such movements in. automatically timed relationship with Vother movements.

Other objects relate to power clamping of movable supports of a milling machine and to the automatic control thereof in timed relationship with other operations in the machine cycle'.

Another object is generally to simplify and improve the construction and operation of milling machines, and still other objects Will be apparent from the specification and claims.

The invention consistsin the particular arrangement and combination of parts herein illus'- trated, described, and claimed, and in such modifications of the illustrated and described structure as may be equivalent to the claims.

In the drawings like reference characters have been applied to the same parts in each of the several views of which:

Fig. 1 is a front elevation of a milling machine in. which the invention is: incorporated.

Fig. .2 is'a right side elevation of the same machine.

j Fig. 3 isV a. sectional View of the machine taken partly Valong Vline 3 3 of Fig. 2,7partly along line ,3c- 3a as to the upper right and left portions,

and along line 3l1 3b as to a lower right-nano.

portion.

Fig. 4 is a sectional view on the line 4 4 of Fig. 2.

Fig. 5 is a sectional view on the line 5 5 of Figs. 1, 3.

Fig. 6 is a sectional view on the line 6 6 of Figs. 2, 8.

Fig. 7 is a sectional View on the line 1 1 of Figs. 2, 8.

Fig. 8 is a horizontal section taken along line 8 8 of Fig. 2.

Fig. 9 is a plan view in part section on the line 9 9 of Fig. 1. v

Fig. 10 is a detail in part section on the line |0 I of Fig. 8.

Fig. l1 is an enlarged transverse section through a valve portion taken along line Il ll of Fig. 8.

' Fig. 12 is an enlarged transverse section through a valve portion taken along line |2 |2 of Fig. 8.

Fig. 13 is a section similar to Fig. 1l, but showing a different position of the valve member.

Fig. 14 is a section similar to Fig. 12, but showing a diierent position of the valve member.

Figs. 15 and 16 are enlarged sectional views of portions of a valve shown in Fig. 4 with the valve member in different positions.

Fig. 17 is a schematic view in the nature of a development showing the operative relation of the parts of the machine.

Fig. 18 is a view in part section of a detail indicated in Figs. 9 and 17.

Figs. 19, 20, and 21 are details of the mechanism indicated in Fig. 17. f

Fig. 22 is a detail in part section of one of the table dogs.

Referring to Figs. 1 and 2, the milling-machine includes a bed'or base I havinga work table 2 mounted for reciprocation thereon to the'right or left in Fig. 1. A head frame 3 is slidably iixed with the bed for horizontal movement transverse to the table movement and means are provided in the form of T-bolts 5 4 and 5 5 engaging suitable slots in bed I for clamping the frame in its various positions. Bolts 4 4 are tightened by suitable nuts in the usual manner but bolts 5 5 are constructed to avoid extending them through the entire height of the frame. Being similar,

only one will be described in detail. As seen in Fig. 1, bolt 5 has a transverse bore 6 at its upper end through which a member 1 extends outside of the frame and threadedly engages a nut 8. Member 'I has an enlarged conical head 9V slidably fitting a bore in frame 3 and engaging a complementary surface formed at the end of bore 6. A sleeve I0 is slidably fitted in frame 3 and has a bore in which member 1 is fitted, the sleeve having a conical end engaging a complementary surface at the other end ofbore 6. Sleeve I3 and member 'I are prevented from rotating by any suitable means,` not shown, and when nut 8 is suitably turned, the conical portions'of member 'I and sleeve I6 are forced toward each other, forming oppositely disposed wedges tending to lift bolt 5 for clamping, there being clearance on the under side of bore 6 to allow such movement of bolt 5. Y

For moving the head frame a screw Il, Figs. 3, 8, and 9, is provided journaled in a bearing I2 xed with bed i and prevented from moving axially therein. Screw I I engages a nut portion' I3 fixed with frame 3 and causes sliding movement.

thereof when it is turned by means of a suitable crank, not shown, applied to the squared portion I4.

Frame 3 supports a spindle carrier I5 slidably guided for vertical movement and having a tool spindle I6 rotatably mounted therein. Means later described are provided for moving carrier I5 vertically and clamping it in the various positions of adjustment.

' Spindle I6 may be rotated by means of the following transmission mechanism. A pulley I7 is xedon a sleeve I8, Figs. 2 and 17,journaled in a suitable bearing'I9 ina member 2B fixed with the bed I, the sleeve I8 also having xed thereon a member 2I constituting a part of a clutch generally denoted by numeral 22. Member 2I drives a shaft 23 through the medium of a member 24 slidably keyed on,v shaft 23 and frictionally engageable with member 2l on surfaces 25 and Z6. Member 24 may be moved into and out of engagement with' member 2I by means of a hand lever 27-xed on a shaft 23 suitably journaled in bed I and having also fixed thereon a lever 29. A ro'd 36 connects' lever 29 with a lever 3l fulcrumed on a shaft 32 journaled in suitable bearings in member 20 and having a member 33, Fig. 1, fixed therewith carrying a pivoted shoe 34 engaging a groove 35, Fig. 2, formed in member 24. Movement of lever 27 up or down will accordingly cause movement of member 24 into or out of engagement respectivelyrlvlith member 2l and thus start or stop rotation lof shaft 23.

Shaft 23 is journaled in suitable bearings in bed'I and drives a shaft 36 by means of a bevel gear 31 slidably keyed upon shaft 23 and having a portion journaled in a brackety 33 fixed with head frame 3 and depending through a slot 39\,-`Fig. 3, in bed-I2 Gear `3`I meshes-with a bevel gear 4i) fixed-on shaft 36. Shaft 35 drives a shaft 4 i, Fig. 1, by means of arate changer, generally denoted by numeral 42, and consisting of a gear 43 removably keyed-to shaft 36 and meshing with la gear 44 removably keyed-to shaft 4E. Gears i3-44 are of `different diameter and are interchangeable to produce different speeds in shaft 4I and may be replaced withother gears of different ratios also interchangeable Ato produce still lother speeds. Shaft 4I drives a shaft 45 by means of a sleeve 4Sfslidably keyed to shaft 45 having a gear 4l fixed therewith and meshing with a gear 48 xed with shaft 4i. Shaft 45 drives spindle I6 through ment of frame 3re1ative to bed I without inter- Y rupting the driving relation between shaft 23 and shaft 36, and spindle carrier I5 maybe adjusted vertically without interrupting the driving connection between shaft 4I and shaft 45, the sliding relation of shaft 45 and sleeve 46, Fig. 1, Valg-Y,y

lowing shaft 45 to move vertically with carrier I5 during such adjustment. A housing Y5I vis provided for the projecting end of shaft 45. Overarms 52-52 may be provided slidably mounted in carrier l5. Transmission mechanism for table 2 is provided including a feed pump of relatively small displacement, generally denoted by the numeral 53, Figs. 2 and 17, and a rapid traverse pump of relatively large displacement, generally denoted by numeral 54. l

Feed pump 53 may be of any suitable type, but in this instance consists of gears 55 and 56, Figs.

` 6 and 17, meshed together within a Vsubstantially closed housing 57, as shown in Figs. 6 and 17,

the housing providing an inlet portV 58 and anV outlet port'59. Gear55 is fixed on a shaft V60 journaled in housing 51 'and gear'56 is freely rotatable on a sleeve 6I fixed in the housing. Pump 53 is connected to be driven through main clutch 22 from shaft 23 by meansrof shaft 60 rotative from shaft 23 by means of a coupling 62. QuickV movement of Y main clutch 22, to exclude the clutch, by means of a train including al gear 6B, Fig. 17, xed'with clutch' member 2I, a gear 70 fixed on a shaft.

TI and meshedwith gear 69, a gear I2 fixed on shaft II and driving a shaft I3 through the medium of an idler.V gear 14, and a gear 'I5 fixed on shaft 'I3 and meshed with idlergear 'I4'. Shaft 'i3 is coupled with shaft 61 by means of a couplingk member 76.

The pumps 53 and 54 are each 'supplied withfluid from a reservoir 77, with which the 'inlet ports of the pumps communicate by means'` of a suction pipe I8 'and other suitable channels.

The inlet port 58 of the feed pump 53 Vreceives fluid from reservoir 'I1 through a feed Vregulating throttle, generally denoted by numeral 19, Figs'. 6

and 17,'and through va cut-off throttle, generallyY denoted'by numeral 80, Fig. 17. j

'Ihe feed regulating or rate control throttle 'I9 consists of a plunger 8| having a taperedV end portion adapted to more or less restrict a throttle e opening 82, in accordance with the-position `of plunger 8l whereby to determine the rate of ow to and from pump 53, as morefully explained in a copending application of Fred A. Parsons, Serial No. 321,250, filed November 22,

1928. A feed cut-off throttle or valve 86 consists of a plunger 83 having an end portion adapted to completely close a channel 84 leading from a reservoir 'El' when the plunger is in the position shown in Fig. 17. Thus the uid flow to the pump 53 may be completely cut off by throttle V8! or may be predetermined in accordance with the position of feed regulatingY throttle I9 kwhen throttle 3i) is open. Throttle 79 may be manually regulated by means Aof a lever 85, Figs. 1, 2, 8, and 17, fixed on a shaft 86 on which is fixed a bevel gear 'lmeshed with a gear 88 xed on` a shaft 89 journaled in a member 90 and having iixed thereon a segment 9| engaging rack teeth in plunger 8|. A pointer 92 is fixed to move with lever`05 and adapted to visibly indicate against a stationary dialY or chart 93'the position of plunger 8|. Chart V93 is preferably graduated in correspondence with thev feed rates resulting from different throttle positions.

The inlet port 65 of quick Vtraverse pump 54 communicates with the fluid reservoir 'Il through a cut-off throttle or valve, generally denoted-by numeral 94, Fig. 17, consisting of a plunger 95 movable for an end portion thereof to open or to completely close a throttle opening 96 communieating with channel 97 leading from suction pipe `13.

, mentV of rate control throttle '|9, while the open- Ving of the quick traverse cut-off throttle provides a quick `traverse rate of delivery from the pumps. The output of pumps 53 and 54 may drive a motor, for driving table 2, generally denoted by the numeral 99, and including a cylinder |00 and a piston |0| fixed on a piston rod |02 which is fixed at its ends |03|04 for movement with table 2. The pump fluid passes to the motor 90 through a reverser valve generally denoted by the; numeral |05, Figs. 6, 17.

Reverser valve |05, as shown in Figs. 6 and 11 to 14 inclusive, consists of a member |00 rotatably fitted in a chamber |01 and having cutaway portions, as particularly shown in Figs. 11 tc 14 inclusive. Y 1

'Ihe channels connecting pumps 53, 54 with motor 99 are as follows: As shown in Figs. 6 and 17, outlet port 59 of feed pump 53 communicates with a channel |00 and outlet port 03 of quick traverse pump 54 also communicates with channelV |00 through a channel |09, Fig. 17. Channel |08 leads into chamber |07 of reverser valve |05 adjacent to ports ||0 and I which communicate respectively with channels ||2 and I I3, Figs. 1, 17, respectively communicating `with the different ports H4 and ||5 of the cylinder |00. A port y| I6 enters the valve chamber at a point between Vthe ports ||0 and III and serves as an exhaust passage for fluid returning from cylinder |00. Referring to Figs. 11 and 13, it will be seen that with valve |05 in the position shown in Fig. 11 uid will pass from passageway I 08 to port IIO and through channel I2, Figs. 1, 17 and port I4 into cylinder |00,` thus forcing piston |0|, piston rod |02 andtable 2 to the right in Fig. 17. Fluid in the right end of cylinder |00 will pass out through port ||5, channel H3, and port |I| to port IIG and be returned to reservoir '|I through a channel II'I, Fig. 17. When valve member |06 is in the position shown .in Fig. 13, the connections will be reversed and liquid will flow to cylinder |00 through port and channel ||3 and port ||5, and be returned to port IIS through port H4, channel ||2 and port |I0, thus moving table 2 to the left.

Fluid exhausting from motor 99 through port |B and channel I'l is forced to pass through an overrun preventing valve, generally denoted by numeral IIB, and a back pressure valve in the form of a spring pressed'ball I9 cooperating with a seat in an outlet port |20.

The operation of overrun prevention valve |I8, Figs. 7, 17, which has been fully described in the above mentioned copending application, Serial No. 321,250, includes a plunger |2| pressed to the right, Fig. 17, by a spring |22 and having` xed thereon a piston head |23 movable in a cylinder I 24. A pipe or channel |25 supplies fluid pressure to oppose spring |22 by means of fluid under pressure derived from a point in channel |08 between pump 53 and reverser valve |05. Plunger |2| provides a throttle opening |20 movable with the plunger to more or less restrict the outlet of uid,

the arrangement being such that as the forward pressure on the motor is decreased, the back pressure is automatically increased by the restriction of the throttle opening whereby a zero or negative forward pressure such as would permit overrun, can never occur. The arrangement also tends to set up pressure on both sides of the motor piston at light or moderate loads whereby to avoid vibration or chatter.

.When valve member |06 is in central position, as shown in Fig. 6, the passages to or from cylinder |00 are closed and table 2 is locked against movement in either direction. At this time a passage |21, Figs. l2 and 14, formed in valve member |00, will register with ports |28 and |29 communicating respectively with passage I 08 through a passage |30 and a passage |3| whereby any fluid coming from eitherv of pumps 53 or 54 will be freely returned to reservoir Reverser valve member |00 may be moved by means of table dogs. |32 or |33 adapted during the course of table movement to contact the one or the other of trip plungers |34 and I 35, plunger |34 having rack teeth respectively engaging a pinion |36 xed on a shaft |31 and a pinion |38 which engages rack teeth on plunger |35. Shaft |37 actuates a sleeve |39, Fig. 17, through a lost motion device, generally denoted by numeral |40, Figs. 1, 2, 9, and 17. and which is later described. Sleeve |39 is journaled in a suitable bearing in member 90 and has a gear segment |4| fixed thereon meshing with rack teeth in a plunger |42 vertically slidable and extending downwardly suilciently to engage a gear segment |43 fixed on reverser valve member |06 whereby motion of either plunger |34 vor |35 will cause rotary movementof member |00.

Reverser valve member |06 may also be moved by a hand lever |44 fixed on the shaft |37.

The arrangement is such that when hand lever |44 is moved to the left, in Fig. 1, uid will be applied to the end of cylinder |00 to move table 2 to the left, in Fig. 1, plunger |34 will be lowered, and through pinion |33. plunger |35 will be raised into the path of a table dog |33. Dog |33 is adjustably fixed on table 2 by means of a T- bolt |45 and T-slot |45 and has a cam surface |41 thereon. Cam surface |41 will during the course of table movement contact plunger |35 at a predetermined point in the table movement, forcing the plunger downwardly and, if no lost motion is provided in device |40, bringing lever |44 to a central position corresponding to the valve position shown in Fig. 6 to stop the table.

When lever |44, Fig. l, is moved to the right, fluid will be applied to the end of cylinder |00 to move table 2 to the right, plunger |34 will be raised and plunger |35 lowered, as above described. Dog |32 fixed on table 2 by means of a T-bolt |48 operating in T-slot |40` and having a cam surface |49 at a predetermined point in le y movement of table 2 contacts plunger |34 by means of surface |99forcing it downwardly and bringing valve member |96 to its central position, as above outlined, and stopping the table.

Automatic reversing of table 2, alternatively available instead of Vthe stop previously described, is provided by the means of the lost motion device |49 which includes lugs |59 and |5|, Fig. 1, i'lxed with sleeve |39, Fig. 9, and having screws |52 and |53 adjustable therein to contact opposite sides of an ear or lug |54 fixed with hand. lever' |49 or to allo-w a predetermined amount of lost motion in either direction. Pinion |35 has a cam portion |55, Fig. 18, having a central notch |56 engaged by a spring'pressed plunger |51. When table 2 is moving, for ex-` ample, to the right, plunger |34 will be contacted at a predetermined point in table travel by the surface |49 of dog |32. Plunger |34 will then be forced downwardly, causing shaft |31 -to turn and sleeve |39 will be moved with shaftA |31V and cam |55, turning valve member |96 towards its central position which it would normally reach at the same time that the central notch of the cam is engaged bythe spring plunger, thereby stopping the table, as `previously noted. But if lost motion is provided at |99, cam |55 will reach its central position before valve member |96, and before movement of the table stops plunger |51 acting against the cam will cause movement of shaft |31,and lever |94 to its extreme leftposition. Similarly, automatic reversal maybe caused to take place in the other direction. Thusin either direction of table movement the table may, at the end of its travel, be brought to a stop or reversed auto- Y matically.

For automatically changing from feed rate to rapid traverse rate the cut-off throttles S9 endet, previously described, are connected for operation from vtable dogs |58 and |59. As inclicated in Fig. 22, each dog is adjustably iXed to table 2 by means of a bolt such as |69 having a T-head engaging T-slot ifi'in table 2, and actuates one of plungers |6| and |62 by means of a latch member |63 pivoted on a stud |69 iixed with the dog. The latch depresses itsplunger when table' 2 moves in one direction by means of a cam surface |65, but whenV table 2 moves in the opposite direction, latch |63 when it encounters its plunger swings about stud |64 and passes over the plunger without aiecting it. A spring |66 'returns latch |63 to the position shown when it has passed the plunger. If the same change in rate is intended to take place at the same point in both directions-of table travel, the dogs may be of solid type. Plungers |9| and |62 are vertically slidable in bed so located as to be contacted by one or another of dogs |58 andV |59, or others of similar or suitable type,V the plungers beingk located at different distances from table 2, Fig. 9, whereby Vdogs may be caused to contact either plunger without aiecting the other, and in either direction of travel ofv the table; Plungers |6| and |62 are connected at their lower ends by a pinion |61, see Figs. 1, 17, 19, 20, and 21, rotatably mounted on shaft |68 and having a portion |69 extending therefrom andhaving abutments |19 and ll|between which passes a pin |12 adjustably fixed to segment |13 and constituting a lost motion device, generally denotedA by. numeral |19, between pinion v|61 and shaft |68. At desiredpoints in the travel o-f table 2y dog |58, or'a similar or suitable dog, may contact plunger |6|, vforcing it downwardly and causing rotation of pinion |61 whereby to close cut-off throttle 89 and at the same time to admit-:duidV dogs such as described may be used to causeA table 2 to proceed at either a rapid traverse rate or at a feed-rate in any part of its stroke in either direction, the dogs merely projectingY sufciently from the table to Contact the desired plunger. 'Y Y Lost motion device |14 Vis provided for the purpose of obtaining instantaneous and positive action of, throttles 89 and 94 regardless Yofthe speedof table travel and movement of plungers |8| and |82. In either direction of Y throttle movement when a dog contacts one of the plungers |6| or |62 and starts to move it downwardly, a cam portion |15 of pinion |61 will rotate for some distance without disturbing the position of provision of lost motionvbetween a portion |19 and a pin |12. However, as soon as cam portion |15 has passed slightly beyond its middle position, a spring plunger |16 acting on theV facecf cam |15 will instantaneously move throttles 89 and 94 to the limit of their travel in the sam direction in which they were moving;

To guard against damage to the mechanism from over pressure, a relief valve is provided'for liuid passage |98 in the form of a spring pressed hall |11 cooperating with a suitable seat in passage |39.

t is desirable that when feed pump 53 is .op-

'ora-ting the fluid pressure should not react on the rapid traverse pump 54 and'to accomplish this purpose discharge port 66 of` rapid traverse pump 59 communicates with passage |98 through k a passage |99 having a one-way va-lveconsisting of a spring pressed ball |18 cooperating with a` suitable seat in passage |99. Y Y

For manually Vraising and lowering carrierA I there is provided a vertical screw |19, Figs. 3 and 1'7, slidably keyed in the hub portion |89of a bevel gear |9| journaled in a portion of head frame 3. Screw |19 engages a nut portion |82 in spindle carrier i5 and-is fixed Vagainst axial `movement relative to a member |33. A shaft .|84

is journaled in head frame 3 and has fixed therewith a bevel gear |85 engaging gear |8|. Shaft |89 may be turned by meansV of a'suitable crank,

not shown, applied to a squared portion |36 thereof. Y Y

Carrier l5 may also be raised and lowered by fluid pressure admitted to a cylinder. |81 formed in the head frame 3 having a piston' |89 Vslidable therein and xed on member |83. Fluidfor cylinder |91 is supplied byja pump |89, Figs. 4 and 17, associated with bracket 38 and which may be segment |13 or plungers 83 and 95 owing to the 30 being of the left-hand type.

. Hi8-and constitutes an exhaust passage.

sage |93 communicates with a suction pipe |96 through the lower portion of a vertical cylinder |91 formed in bracket member 38 and draws iluid from a reservoir |98 fixed with member 20 and extending under member 38 in all positions of sliding adjustment thereof. Discharge passage |94 communicates through a one-way valve consisting of a spring pressed ball |99 cooperating with a suitable seat in a chamber 299 having a port 29| leading into an accumulator, generally denoted Vby numeral 292, and including above mentioned cylinder |91 and piston 293 pressed upwardly by spring 294 and designed to maintain underV pressure suflcient fluid to meet the instantaneous requirements of cylinder |81.

In order to prevent power loss at times when there is no draftof fluid on pump |89, inlet passage |93 enters cylinder |91 at such a point that piston 203 will, when accumulator cylinder |91 is charged with fluid-cover the entrance to passage |93 whereby no fluid `will be admitted to pump |89 until further draft' is made on the fluid stored in the accumulator. Pressure in chamber 299 is prevented from acting against the gears of pump |89 underthese conditions by the one-way valve |99.

Movement of carrier|5 from pump |89 is controlled by a reverser valve 205, Figs. 4, 15, 16, 17, having a rotatable member 296 with cut away portions, asrmore particularly shown in Figs. 15 and 16, tted in a suitable chamber 291. A port 2 98 leads from chamber 299 into chamber 291 and a port V299 leads froma point in chamber 291 adjacent to port 208 to a passage 2I9 communicating with the lower end of cylinder |81. Another port 2| I leads from chamber 281 to a passage 2 I2 leading to the upper end of cylinder |81. A port 2|3 leads from chamber 291 to reservoir When valve member 296 is in the position shown in Fig. 15,fl'ui`d will pass from pump |89 through port 298, chamber 291, port 299 and passage 2|!) into cylinder |81 below piston |88 thereby raising member |83, screw |19 and carrier I5. Fluid from the'upper end of cylinder |81 will be forced Y through passage 2I2 and port 2| to chamber 201,

Fig. 15, and pass to reservoir |98 through exhaust port 2|3. When member 296 is in the position shown Fig. 16, fluid will pass from pump |89 through port 298, Yport 2II, and passage 2|2 to cylinder |81 above piston |88, thus forcing member |83 downwardly and lowering screw |19 and carrier I5. Fluid from beneath piston |88 will be forced through passage 2|9 to port 299 through chamber 291 to exhaust port 2 I3 and be returned to reservoir |98.

Carrier |5 may be clamped when in its lower position by bolts 2I4-2 I 4, Figs. 3, 5, and 17, axially slidable in the carrier I5 and vertically movable therewith, each comprising sections 2 I5 and 2I6 axially opposed and threadedly Y engaging couplings 2|1-2|1. Bolt sections 2|5 and 2|6 Ahaveheads engaging T-slots 2|8 and 2|9 formed in the inner walls of frame 3 wherebywhen couplings 2|1 are turned the sides of frame 3 will be sprung togethersufciently to tightly clamp carrier I5 therebetween, the threads on section 2I6 'I'he couplings 2 I 1 2|1 areV turned by fluid pressure by means of a cylinder 229, Fig. 5, having a piston 22| fixed on a rod 222 having rack teeth 223 and 224 formed ,at its ends and engaging gear teeth formed in couplings 2|1-2|1. Rod 222 is adjustable in length being formed in two sections 225 and 226 j oinedby a coupling 221 interposed between the sections. Admission of uid to one end of cylinder 229 will accordingly move piston 22 and rod 222 in one direction and rotate couplings 2|12 I1 to tighten bolts 2 I4-2I4 while admission of fluid to the other end of cylinder 229 will cause piston 5 22| and rod 222 to move in the opposite direction and loosen bolts 2 |4--2 |4.

Fluid for clamping carrier I5 when in its lower position is supplied to cylinder 229 from the pump |89 which moves the carrier and is controlled on the same reverser valve 295 which controls carrier movement. With the valve 295 in the position shown in Fig. 16, that is to say, in the position which is effective to move the carrier downwardy iluid then supplied under pressure to channel 2| I moves a plunger 228, Fig. 17, against the pressure of a spring 229, thereby uncovering a port 230 which communicates with cylinder 229 through a passage 23| and a pipe 232, Fig. 5, slidable in a bore 233 which communicates with the right end 20 of cylinder 229 through channel 234. With this adjustment of valve 295 piston 22| will be moved to the left and bolts 2|4-2I4 will be tightened. Under these conditions fluid in the left end of cylinder 229 will pass out through a channel 235 25 to a bore 236 and through a pipe 231 slidably fitted therein to a passage 238, Fig. 17, communicating with the port 299 of valve 295 and through chamber 291 and port 2| 3 to reservoir |98.

Carrier I5 is also unclamped by the means of 30 iiuid from the pump |89 and controlled from the reverser valve 295. With valve 295 in the position shown in Fig. 15, fluid will pass from port 299 through passage 238, Fig. 17, pipe 231, Fig. 5, bore 236, and channel 235 to the left end of cylinder 229, thus moving piston 22| and rod 222 to the right and loosening bolts 2|4-2I4. Under these conditions fluid in theA right end of cylinder 229 will pass out through the channel 234, bore 233, pipe 232, and port 239. At this time channel 2| I, Fig. 15, is in communication through the reverser valve 295 with exhaust port 2I3 whereby there will be substantially no pressure opposing spring 229. .The plunger 228 will accordingly be forced down by spring 229 and communication will thereby be established between port 239 and a groove or channel 239, Fig. 17, formed inthe side of plunger 228, whereby the'uid escapes into the upper end of a bore 249 in which plunger 228 moves and into 'reservoir |98 through a paS- sage 24|.

The purpose of plunger 228 is to insure that carrier l5 will not be clamped with frame 3 until it has reached its Vlowermost position. The spring 229 is of sumcient strength that it will not be overcome to admit clamping fluid through port 239 until the piston |88 and the carrier have reached the limit of downward travel.

. The reverser valve 295 is operable manually from the front of the machine'by means of a hand lever 242 xed on a shaft 243 journaled in a portion of bed and having a gear 244 fixed thereon in driving relation with a gear 245 flxed on a shaft 246 keyed in telescopic relation with a sleeve 241 adapted to permit sliding adjustment 65 of frame 3 while maintaining the driving relation between shaft 246 and shaft 248. The sleeve 241 is xed with a shaft 248 connected with valve member 2976. Valve member 296 is never intended to remain in an intermediate position and to insure that it shall always take either the position shown in Fig. 15 or that shown in Fig. 16, a detent is provided consisting of a `cam `249, Figs. `10 and 17, xed on shaft 243 and a spring pressed plunger 259.

V*lteverservvalve 205 may also be automatically shifted from table dogs such as 25| and 252, Fig. 1, as follows: A pair of vertically movable ,plungers 253 and 254, Figs. 1, 9, vand 17, is provided at theirV lower ends with suitable rack teeth engaging opposite sides Vof a pinion 255 fixed on the shaft 243. By contact of suitable dogs either plunger may be moved to move valve 205 inthe one or the other direction at any time during tableY movement; Ordinarily this is done somewhat before the limits of forward and reverser movement to unclamp and raise carrier I 5 before reverse movement and to lower and clamp the y carrier before forward movement.

This may be done by suitably locating dogs 25| and 252 with relation to dogs |32 and |33 whereby the plungers lwill be depressed in the proper sequence to bring about the above outlined results, or it may be done in other ways, for example, it is contemplated that dogs such as 256 and 25'! might'be utilized, dog 256 having cam surfaces 258 and 259 adapted to contact both plungers |34 and 253, plunger 253 preferably slightly in advance of plunger |34 whereby to reverse or' stop table 2 promptly after raising of spindle carrier I5, and dog 251 having cam surfaces 260 and 26| adapted to contact respectively plungers |35 and 254, preferably plunger 254 Vslightly in v advance of plunger |35 whereby to reverse or stop table, 2 promptly after lowering of spindle car-V unclam'ped and raised during the time table 2V was moving to theright, but it is contemplated that other dogs not shown could be provided for producing the opposite result, namely, lowering the spindle during progress of the table to .the right,jand raising it during movement of the table to' the left.

By properly positioning dogs'25l and 252 and others, if necessary, of similar construction, not shown, the carrier may also be raised and lowered at intermediate points inthe table movement for the cutter to pass overraised work portions forpinstance.

What is claimed is: j l

'1.' InaV milling machine Ythe combination of a stationary support, a horizontally reciprocable work table supported therefrom, a. tool spindle rotatably supported from said stationary support, said spindle andtable being relatively bodily vertically movable in directions respectively to increase and to decrease the spacing thereof, a power'source, a power train for rotation of said spindle, 'a power train for said horizontal table movement, clamp means adjustable to a plurality of positions, one of which is adapted to clamp said spindle and table against said relative bodily movement, Ya power train operable from saidA source for veither direction of said bodily vertical movement, means limiting said bodily vertical movement in one direction connectible for adjustment'of said clamp means to said clamping position and means operable to prevent'the connection of the last mentioned power train until said limiting means isV inoperation.

Y,2. In a' milling machine the combination of a delivery until said limiting means is operative.

3. In a milling machine the combination of a stationary support, a horizontal work table reciprocably supported from said stationary support, a spindle carrier slidably supported from said stationary support and vertically bodilyv adjustable, a horizontal tool spindle rotatably supported from said spindle carrier, a power train for rotation of saidspindle, a power train forrsaid horizontal movement of said work table, a power train for said vertical bodily carrier movement including a source of uid supply, a motor operable therefromand valve means controllingV the operation thereof, automatic control means for the last mentioned kpower train and operable in accordance with said horizontal table movement to shift said valve means, clamp-meansadjustable tol two positions, one of which Vis'operable to x said carrier against vertical movement. a power train for adjustment of said clamp means including a uid operable device and asource of fluid pressure, and control means for the last mentioned power train including a valve meansV controlling delivery of'uid fromsaid pressure source to said fluid operable device, and means controlling the operation of the last mentioned valve means in accordance with vthe operation of power source and a motion interruptingdevice,V

a table transmission including alternative feed Yrate and relative rapid traverse 'rate trains each driven from said power source, clamp means'adjustable to aplurality of positions onerof which is operative to prevent said relativeY bodily movement of said spindle and table, a power train driven from said power source and connectible for said bodily relative vertical movement Vofvrsaid spindle and table, and control means including means preventing adjustment of said clamp meansinto said one position thereof .during `said' bodily relative movement of said spindle Vand table from said power train.

5. VIn a milling,machine,'the combination of a, horizontally vreciprocabl'e work support, a Vtool spindle, transmission mechanism for alternatively moving said work support atrelatively Vslow kcutting rate or at relatively fast rate, transmission mechanism for relative vertical movement of said support and spindle to alternative cutting and non-cutting positions, clamp means Yoperable to alternative positions respectivelyto restrain and to permit said relative movement, a power train for the operation of said clamp means, control means for each of saidtransmissions and Yoperable in accordance with the movement of said support and at an-intermediate point 5in" the unidirectional movementv thereof,

and control means for said power train and operable to eiect the position of said clamp means restraining said relative movement whenever said support and spindle are in said cutting position.

6. In a milling machine, the combination of a stationary support, a horizontally reciprocable work table supported therefrom, a tool spindle rotatably supported from said stationary support, said spindle and table being relatively bodily vertically movable in directions respectively to increase and decrease the spacing thereof, a power train for rotation of said spindle, a second power train for said table movement, a third power train for said relative vertical movement, a stop for limiting said relative vertical movement and adjustable for altering the limiting point thereof, control means for said third power train and operable to eect said relative movement in a direction against said stop, means limiting the pressure eiective on said stop from said third power train, clamp means shiftable to a position eiective to clamp said spindle and table against said relative movement, and a fourth power train connectible for shifting said clamp means to said position.

'7. A milling machine as specied in claim 6 including means operative in accordance with the horizontal movement of the table for connecting the fourth power train.

Y 8. A milling machine as specified in claim 6 including means operative in accordance with the horizontal movement of the table for con- 15 necting both the third and fourth power trains. FRED A. PARSONS.

CERTIFICATE OF CORRECTION.

Patent No. 2,052,648.

FRED A. PARSONS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6, first column, line 11, for the word "reverser" read reverse; and line 65, claim l, after "direction" insert the comma and words a power train; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 1st day of December, A. D. 1.95.6e

Henry Van Arsdale (Seal) Acting Commissioner of Patents,

September l, 1956. 

